下载本文件
本文件将获取屏幕图像数据的所有代码整合到两个文件中（ScreenRecorder.h和ScreenRecorder.cpp），使获取屏幕图像数据变得简单。输出IYUV视频流。还可以获取系统播放的声音，输出PCM音频流。由于使用了MFC类，本文件只适用于MFC程序。
使用方法
1.创建MFC项目。
2.将ScreenRecorder.h和ScreenRecorder.cpp文件复制到你的MFC项目目录下。
3.将ScreenRecorder.h和ScreenRecorder.cpp文件添加到项目。
4.包含ScreenRecorder.h头文件，声明ScreenRecorder类对象。对象应在录屏生命周期内不被析构掉，比如放在对话框头文件对话框类定义中。
ScreenRecorder SR;
5.声明SR_INIT初始化结构，填写结构参数。提供录制区域矩形，可以是整个屏幕，也可以是屏幕的某个区域。提供录制帧率。提供样本输出函数。创建“停止”和“退出”事件，提供事件句柄。
int VideoSample(BYTE* pB, LONG len)//视频样本输出函数
{return 0;
}int AudioSample(BYTE* pB, LONG len)//音频样本输出函数
{return 0;
}HANDLE hStop = CreateEvent(NULL, TRUE, TRUE, NULL);//创建“停止”事件。手动重置HANDLE hExit = CreateEvent(NULL, TRUE, FALSE, NULL);//创建“退出”事件。手动重置CRect rect;rect.left=0;rect.top=0;rect.right=1920;rect.bottom=1080;SR_INIT SrInit;//SR初始化结构SrInit.rect = rect;//录制矩形SrInit.ShowCursor = TRUE;//TRUE显示光标，FALSE不显示SrInit.nFramePerSec = 30;//视频帧率SrInit.VideoSample = (MYPROC_VideoSample)VideoSample;//视频样本输出函数SrInit.AudioSample = (MYPROC_AudioSample)AudioSample;//音频样本输出函数SrInit.hStop = hStop;//“停止”事件句柄SrInit.hExit = hExit;//“退出”事件句柄
6.运行。调用初始化函数创建录屏线程，如果提供了音频样本输出函数，还将创建录制系统声音线程。设置“停止”无信号后，视频和音频样本输出函数将被反复调用；函数参数1为样本缓冲区指针，参数2为样本的字节大小。
SR.Init(SrInit);//使用初始化结构作为参数，调用初始化函数ResetEvent(hStop);//设置“停止”无信号
7.暂停。此时，样本输出函数将停止调用，但录屏线程仍然存在。
SetEvent(hStop);//设置“停止”有信号
8.停止。将退出录屏线程。
SetEvent(hStop);//设置“停止”有信号SetEvent(hExit);//设置“退出”有信号
代码没有提供样本时间戳，视频一个样本就是一个IYUV视频帧，根据帧数量就可以计算出当前的样本时间：
int index=0;//帧索引double dur=(double)10000000/(double)30;//1帧的持续时间，单位100纳秒。30为帧率LONGLONG SampleTime=(LONGLONG)(dur*index);//当前的样本时间，单位100纳秒index++;
音频样本为若干音频帧。音频为2声道，16位PCM，采样率48000。一个音频帧占4字节，根据累计的音频帧数量，可以计算出音频样本的当前时间：
int FrameCount=0;double Adur=(double)10000000/(double)48000;//1帧的持续时间，单位100纳秒LONGLONG ASampleTime=(LONGLONG)(Adur*FrameCount);//当前的样本时间，单位100纳秒FrameCount+=len/4;//len为此次样本的字节大小
本文件的使用示例，可以看Windows应用-屏幕录像。
ScreenRecorder.h文件的全部代码
#pragma once#include "mmsystem.h"
#pragma comment(lib, "winmm.lib")#include "D3D11.h"
#pragma comment(lib, "D3D11.lib")
#include "DXGI1_2.h"
#pragma comment(lib, "DXGI.lib")#include "mmdeviceapi.h"
#include "audioclient.h"#ifndef SAFE_RELEASE
#define SAFE_RELEASEtemplate <class T> void SafeRelease(T** ppT)
{if (*ppT){(*ppT)->Release();*ppT = NULL;}
}#endif //SAFE_RELEASEtypedef int(__cdecl *MYPROC_VideoSample)(BYTE* pB, LONG len);
typedef int(__cdecl *MYPROC_AudioSample)(BYTE* pB, LONG len);struct SR_INIT
{CRect rect;//录制区域矩形BOOL ShowCursor = TRUE;//为TRUE，显示光标UINT nFramePerSec;//每秒帧数MYPROC_VideoSample VideoSample = NULL;//视频样本接收函数指针MYPROC_AudioSample AudioSample = NULL;//音频样本接收函数指针HANDLE hStop = NULL;//“停止”事件句柄HANDLE hExit = NULL;//“退出”事件句柄
};class ScreenRecorder
{
public:SR_INIT mInit;//初始化信息结构ScreenRecorder();~ScreenRecorder();BOOL Init(SR_INIT init);DWORD GetAudioEndpoint();//获取音频端点HRESULT GetScreenData();//获取屏幕图像数据void DrawCursor(BYTE* pB);//绘制光标int ScreenWidth = GetSystemMetrics(SM_CXSCREEN);//获取主显示器的宽度，以像素为单位int ScreenHeight = GetSystemMetrics(SM_CYSCREEN);//获取主显示器的高度，以像素为单位UINT len;ID3D11Device* p3D11Device = NULL;ID3D11DeviceContext* p3D11DeviceContext = NULL;IDXGIOutputDuplication *pDuplication = NULL;BYTE* pPreBuffer = NULL;//不包含光标的图像缓冲区BYTE* pDrawCursorBuffer = NULL;//包含光标的图像缓冲区BYTE* pBuffer1 = NULL;//视频输出缓冲区BYTE* pBuffer2 = NULL;//音频缓冲区HANDLE hVideoThread = NULL;HANDLE hAudioThread = NULL;IAudioClient *pAudioClient = NULL;IAudioCaptureClient *pCaptureClient = NULL;REFERENCE_TIME nDur;//音频包传递默认时间间隔，100纳秒单位LONG BufferSize;//音频样本缓冲区大小，单位字节CBitmap bmp;//用于绘制光标CDC mDC;//内存DC，用于绘制光标int mState = 0;//状态标志。0停止，1运行，2暂停
};ScreenRecorder.cpp文件的全部代码
#include "stdafx.h"
#include "ScreenRecorder.h"ScreenRecorder::ScreenRecorder()
{HRESULT hr = CoInitialize(NULL);//初始化COM库if (hr != S_OK){MessageBox(NULL, L"COM库初始化失败！", L"ScreenRecorder", MB_OK);}D3D_DRIVER_TYPE driver_types[] ={D3D_DRIVER_TYPE_HARDWARE,D3D_DRIVER_TYPE_WARP,D3D_DRIVER_TYPE_REFERENCE,};UINT n_driver_types = ARRAYSIZE(driver_types);D3D_FEATURE_LEVEL feature_levels[] ={D3D_FEATURE_LEVEL_11_0,D3D_FEATURE_LEVEL_10_1,D3D_FEATURE_LEVEL_10_0,D3D_FEATURE_LEVEL_9_1};UINT n_feature_levels = ARRAYSIZE(feature_levels);D3D_FEATURE_LEVEL feature_level;hr = D3D11CreateDevice(NULL, D3D_DRIVER_TYPE_HARDWARE, NULL, 0, feature_levels, n_feature_levels, D3D11_SDK_VERSION, &p3D11Device, &feature_level, &p3D11DeviceContext);IDXGIDevice* pIDXGIDevice = NULL;if (hr == S_OK){hr = p3D11Device->QueryInterface(__uuidof(IDXGIDevice), reinterpret_cast<void**>(&pIDXGIDevice));//获取对应的DXGI设备接口}IDXGIAdapter* pDXGIAdapter = NULL;if (hr == S_OK){hr = pIDXGIDevice->GetParent(__uuidof(IDXGIAdapter), reinterpret_cast<void**>(&pDXGIAdapter));//获取DXGI设备适配器}SafeRelease(&pIDXGIDevice);IDXGIOutput* pDXGIOutput = NULL;if (hr == S_OK){hr = pDXGIAdapter->EnumOutputs(0, &pDXGIOutput); //获取设备输出接口}SafeRelease(&pDXGIAdapter);DXGI_OUTPUT_DESC _output_des;if (hr == S_OK){hr = pDXGIOutput->GetDesc(&_output_des);//获取设备输出描述}IDXGIOutput1* pDXGIOutput1 = NULL;if (hr == S_OK){hr = pDXGIOutput->QueryInterface(__uuidof(pDXGIOutput1), reinterpret_cast<void**>(&pDXGIOutput1));}SafeRelease(&pDXGIOutput);if (hr == S_OK){hr = pDXGIOutput1->DuplicateOutput(p3D11Device, &pDuplication);//根据设备输出接口创建一个duplication接口}SafeRelease(&pDXGIOutput1);if (hr != S_OK)MessageBox(0, L"DXGI初始化失败", L"屏幕录像", MB_OK);len = ScreenWidth * ScreenHeight * 4;pBuffer1 = new BYTE[len]; pPreBuffer = new BYTE[len]; pDrawCursorBuffer = new BYTE[len];bmp.CreateBitmap(ScreenWidth, ScreenHeight, 1, 32, NULL);mDC.CreateCompatibleDC(NULL);mDC.SelectObject(&bmp);
}ScreenRecorder::~ScreenRecorder()
{SafeRelease(&p3D11Device); SafeRelease(&pDuplication); SafeRelease(&p3D11DeviceContext);SafeRelease(&pAudioClient); SafeRelease(&pCaptureClient);delete[] pBuffer1; delete[] pPreBuffer; delete[] pDrawCursorBuffer;if (pBuffer2)delete[] pBuffer2;CoUninitialize();//关闭COM库mDC.DeleteDC();
}DWORD ScreenRecorder::GetAudioEndpoint()//获取音频端点
{SafeRelease(&pAudioClient); SafeRelease(&pCaptureClient);HRESULT hr;IMMDeviceEnumerator *pEnumerator = NULL;hr = CoCreateInstance(__uuidof(MMDeviceEnumerator), NULL, CLSCTX_ALL, __uuidof(IMMDeviceEnumerator), (void**)&pEnumerator);//创建设备枚举器IMMDevice *pDevice = NULL;if (hr == S_OK){hr = pEnumerator->GetDefaultAudioEndpoint(eRender, eConsole, &pDevice);//获取默认音频端点设备}SafeRelease(&pEnumerator);if (hr == S_OK){hr = pDevice->Activate(__uuidof(IAudioClient), CLSCTX_ALL, NULL, (void**)&pAudioClient);//激活默认音频端点设备}SafeRelease(&pDevice);WAVEFORMATEX wfx;wfx.wFormatTag = 1;wfx.nChannels = 2;wfx.nSamplesPerSec = 48000;wfx.nAvgBytesPerSec = 48000 * 4;wfx.nBlockAlign = 4;wfx.wBitsPerSample = 16;wfx.cbSize = 0;if (hr == S_OK){hr = pAudioClient->Initialize(AUDCLNT_SHAREMODE_SHARED, AUDCLNT_STREAMFLAGS_LOOPBACK, (REFERENCE_TIME)10000000, 0, &wfx, NULL);//创建端点缓冲区，可以容纳1秒的音频数据}REFERENCE_TIME r2;if (hr == S_OK){hr = pAudioClient->GetDevicePeriod(&nDur, &r2);//获取单个音频包持续时间，单位100纳秒}UINT32 Size;if (hr == S_OK){hr = pAudioClient->GetBufferSize(&Size);//获取申请的端点缓冲区总大小，单位音频帧}if (hr == S_OK){BufferSize = (LONG)(Size * wfx.nChannels * 2 * nDur / 10000000);//计算样本大小，单位字节if (pBuffer2 == NULL)pBuffer2 = new BYTE[BufferSize];hr = pAudioClient->GetService(__uuidof(IAudioCaptureClient), (void**)&pCaptureClient);//获取音频服务}if (hr != S_OK){SafeRelease(&pAudioClient); SafeRelease(&pCaptureClient);MessageBox(NULL, L"获取音频端点失败！", L"提示", MB_OK);return 0;}return 1;
}void ScreenRecorder::DrawCursor(BYTE* pB)//绘制光标
{CURSORINFO CursorInfo;CursorInfo.cbSize = sizeof(CURSORINFO);if (!GetCursorInfo(&CursorInfo))return;//获取光标的信息if (CursorInfo.flags != CURSOR_SHOWING)return;//如果光标没有显示，不绘制光标bmp.SetBitmapBits(len, pB);mDC.DrawIcon(CursorInfo.ptScreenPos, CursorInfo.hCursor);//在内存DC绘制光标BITMAPINFOHEADER Hdr;Hdr.biSize = sizeof(BITMAPINFOHEADER);Hdr.biWidth = ScreenWidth;Hdr.biHeight = -ScreenHeight;Hdr.biPlanes = 1;Hdr.biBitCount = 32;Hdr.biCompression = BI_RGB;Hdr.biSizeImage = len;Hdr.biXPelsPerMeter = 0;Hdr.biYPelsPerMeter = 0;Hdr.biClrUsed = 0;Hdr.biClrImportant = 0;GetDIBits(mDC.m_hDC, (HBITMAP)bmp, 0, ScreenHeight, pB, (BITMAPINFO*)&Hdr, DIB_RGB_COLORS);//将内存DC位图的位 复制到pB
}HRESULT ScreenRecorder::GetScreenData()//获取屏幕图像数据
{IDXGIResource* pIDXGIResource = NULL;DXGI_OUTDUPL_FRAME_INFO frame_info;HRESULT DuplicationHr = pDuplication->AcquireNextFrame(0, &frame_info, &pIDXGIResource);//获取下一个桌面映像D3D11_TEXTURE2D_DESC frame_desc;DXGI_MAPPED_RECT mapped_rect;IDXGISurface *dxgi_surface = NULL;HRESULT MapHr = S_FALSE;if (DuplicationHr == S_OK){ID3D11Texture2D *_image = NULL;HRESULT Texture2DHr = pIDXGIResource->QueryInterface(__uuidof(ID3D11Texture2D), reinterpret_cast<void **>(&_image));//获取一帧图像纹理SafeRelease(&pIDXGIResource);if (Texture2DHr == S_OK){_image->GetDesc(&frame_desc);frame_desc.MipLevels = 1;frame_desc.ArraySize = 1;frame_desc.SampleDesc.Count = 1;frame_desc.Usage = D3D11_USAGE_STAGING;frame_desc.BindFlags = 0;frame_desc.CPUAccessFlags = D3D11_CPU_ACCESS_READ;frame_desc.MiscFlags = 0;ID3D11Texture2D *new_image = NULL;HRESULT NewHr = p3D11Device->CreateTexture2D(&frame_desc, NULL, &new_image);//创建新的纹理if (NewHr == S_OK){p3D11DeviceContext->CopyResource(new_image, _image);//拷贝图像HRESULT SurfaceHr = new_image->QueryInterface(__uuidof(IDXGISurface), (void **)(&dxgi_surface));SafeRelease(&new_image);if (SurfaceHr == S_OK){MapHr = dxgi_surface->Map(&mapped_rect, DXGI_MAP_READ);//将图像从GPU映射到内存中if (MapHr == S_OK){CopyMemory(pPreBuffer, mapped_rect.pBits, len);}}}SafeRelease(&_image);}}BYTE* RGB32_data;if (MapHr == S_OK)//如果获取图像和映射成功{RGB32_data = mapped_rect.pBits;//直接在mapped_rect.pBits中绘制光标}else//如果失败{CopyMemory(pDrawCursorBuffer, pPreBuffer, len);//复制上一帧图像到pDrawCursorBufferRGB32_data = pDrawCursorBuffer;//在pDrawCursorBuffer中绘制光标}if (mInit.ShowCursor)//如果要求显示光标{DrawCursor(RGB32_data);//在RGB32_data中绘制光标}int iY = 0;int YSize = mInit.rect.Width() * mInit.rect.Height();int iU = YSize;int iV = YSize + YSize / 4;BYTE Color32[4];for (int y = mInit.rect.top; y < mInit.rect.bottom; y++)//将指定矩形内的RGB32数据转换为IYUV存储在pBuffer1{for (int x = mInit.rect.left; x < mInit.rect.right; x++){CopyMemory(Color32, &RGB32_data[y * ScreenWidth * 4 + x * 4], 4);pBuffer1[iY] = (BYTE)(0.299 * Color32[2] + 0.587 * Color32[1] + 0.114 * Color32[0]);//Yif ((x & 1) && (y & 1)){pBuffer1[iU] = (BYTE)(-0.1687 * Color32[2] - 0.3313 * Color32[1] + 0.5 * Color32[0] + 128);//UpBuffer1[iV] = (BYTE)(0.5 * Color32[2] - 0.4187 * Color32[1] - 0.0813 * Color32[0] + 128);//ViU++; iV++;}iY++;}}if (MapHr == S_OK){dxgi_surface->Unmap();}SafeRelease(&dxgi_surface);if (DuplicationHr == S_OK){pDuplication->ReleaseFrame();//释放桌面映像}mInit.VideoSample(pBuffer1, (LONG)(mInit.rect.Width() * mInit.rect.Height() * 1.5));//调用外部函数，发送视频样本。如果获取桌面图像成功，发送新的图像；失败发送上一帧图像return DuplicationHr;
}DWORD WINAPI ScreenRecorderThread(LPVOID lp)
{ScreenRecorder* pSR = (ScreenRecorder*)lp;LONGLONG index = 0; double Ntime = (double)1000 / (double)pSR->mInit.nFramePerSec;DWORD STAR = timeGetTime();//记录开始时间
Agan:DWORD Cur = timeGetTime() - STAR;//当前时间，单位毫秒DWORD Sur = (DWORD)(Ntime * (double)index);//帧呈现时间，单位毫秒if (Cur < Sur)goto Agan;//如果没有到帧显示时间，等待if (Cur >= (DWORD)(Ntime * (double)(index+1)))//如果当前时间大于下一帧的呈现时间{pSR->mInit.VideoSample(pSR->pBuffer1, (LONG)(pSR->mInit.rect.Width() * pSR->mInit.rect.Height() * 1.5));index++;goto Agan;}DWORD mStop = WaitForSingleObject(pSR->mInit.hStop, 0);if (mStop == WAIT_OBJECT_0)//如果“停止”有信号{pSR->mState = 2;//状态为暂停}else{pSR->mState = 1;//状态为运行HRESULT hr = pSR->GetScreenData();}DWORD mExit = WaitForSingleObject(pSR->mInit.hExit, 0);if (mExit == WAIT_OBJECT_0)//如果“退出”有信号{pSR->mState = 0;//状态为停止return 1;}index++;goto Agan;
}DWORD WINAPI AudioEndpointThread(LPVOID lp)
{ScreenRecorder* pSR = (ScreenRecorder*)lp;HRESULT hr; LONGLONG index = 0; BOOL Run = FALSE, Stop = TRUE; double Ntime = (double)pSR->nDur / (double)10000;DWORD STAR = timeGetTime();//记录开始时间
Agan:DWORD Cur = timeGetTime() - STAR;//当前时间，单位毫秒DWORD Sur = (DWORD)(Ntime * (double)index);//帧呈现时间，单位毫秒if (Cur < Sur)goto Agan;//如果没有到间隔时间（间隔10毫秒），等待DWORD mExit = WaitForSingleObject(pSR->mInit.hExit, 0);if (mExit == WAIT_OBJECT_0){return 1;}DWORD mStop = WaitForSingleObject(pSR->mInit.hStop, 0);if (mStop == WAIT_OBJECT_0)//如果“停止”有信号{if (Stop == FALSE){Stop = TRUE; Run = FALSE;hr = pSR->pAudioClient->Stop(); //停止音频流hr = pSR->pAudioClient->Reset();//刷新所有挂起的数据}}else//如果“停止”无信号{if (Run == FALSE){Run = TRUE; Stop = FALSE;hr = pSR->pAudioClient->Start(); //启动音频流}DWORD flags; UINT32 numFramesAvailable = 0; BYTE *pData = NULL;//音频包缓冲区指针UINT32 packetLength = 0;//音频包大小，单位音频帧hr = pSR->pCaptureClient->GetNextPacketSize(&packetLength);//获取音频包的大小，单位音频帧if (packetLength != 0)//如果获取到音频包，将音频包数据转换为short类型，复制到缓冲区{hr = pSR->pCaptureClient->GetBuffer(&pData, &numFramesAvailable, &flags, NULL, NULL);//获取当前音频包的指针if (hr == S_OK && numFramesAvailable != 0 && pData != NULL){int count = numFramesAvailable * 4 / pSR->BufferSize;//计算需要发送多少个样本for (int i = 0; i < count; i++){pSR->mInit.AudioSample(pData + i*pSR->BufferSize, pSR->BufferSize);}hr = pSR->pCaptureClient->ReleaseBuffer(numFramesAvailable);//释放音频包}}else//如果当前没有音频流，将音频缓冲区全部置0{memset(pSR->pBuffer2, 0, pSR->BufferSize);pSR->mInit.AudioSample(pSR->pBuffer2, pSR->BufferSize);//发送10毫秒的0数据}}index++;goto Agan;
}BOOL ScreenRecorder::Init(SR_INIT init)
{DWORD dwV = WaitForSingleObject(hVideoThread, 0);if (dwV == WAIT_TIMEOUT)return FALSE;//如果线程已存在，返回DWORD dwA = WaitForSingleObject(hAudioThread, 0);if (dwA == WAIT_TIMEOUT)return FALSE;if (init.hExit == NULL || init.hStop == NULL){MessageBox(NULL, L"必须提供“停止”和“退出”事件句柄", L"写MP4", MB_OK); return FALSE;}if (init.VideoSample == NULL){MessageBox(NULL, L"必须提供视频样本输出函数", L"写MP4", MB_OK); return FALSE;}mInit = init;mInit.rect.NormalizeRect();//使其为正常矩形（宽度和高度为正值）if (mInit.rect.left < 0)mInit.rect.left = 0;if (mInit.rect.top < 0)mInit.rect.top = 0;if (mInit.rect.right > ScreenWidth)mInit.rect.right = ScreenWidth;if (mInit.rect.bottom > ScreenHeight)mInit.rect.bottom = ScreenHeight;if (mInit.rect.Width() % 2)//确保录制矩形宽度为偶数{if (mInit.rect.right != ScreenWidth)mInit.rect.right += 1;else if (mInit.rect.left != 0)mInit.rect.left -= 1;}if (mInit.rect.Height() % 2)//确保录制矩形高度为偶数{if (mInit.rect.bottom != ScreenHeight)mInit.rect.bottom += 1;else if (mInit.rect.top != 0)mInit.rect.top -= 1;}ResetEvent(mInit.hExit);//设置“退出”无信号SetEvent(mInit.hStop);//设置“停止”有信号hVideoThread = CreateThread(NULL, 0, ScreenRecorderThread, this, 0, NULL);//创建录屏线程if (mInit.AudioSample)//如果提供了音频样本输出函数，创建录制系统播放的声音线程。不提供该函数，则不创建{GetAudioEndpoint();//获取音频端点hAudioThread = CreateThread(NULL, 0, AudioEndpointThread, this, 0, NULL);//创建录制系统播放的声音线程}return TRUE;
}
